Isolation, Identification of Alternaria alternata causing Leaf Blight in Chrysanthemum and its Management

Author: Sowmya M., S. Narasimha Rao, A. Snehalatha Rani and T. Suseela

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Abstract

Alternaria alternata causing Alternaria blight is one of the most widely spread and destructive disease of chrysanthemum (Chrysanthemum indicum L.). The pathogen induces leaf blight and leaf spot which accounts for about up to 80% yield losses, in field also in market condition. Hence experiments are conducted to determine the efficacy of fungicides and bioagents in vitro using poison food technique for fungicides and dual culture method for bioagents. Among the non-systemic fungicides, the highest mean growth inhibition was observed with mancozeb (89.73%) followed by copper oxychloride on radial growth and per cent growth inhibition (15.66 mm and 82.60%) and propineb (15.42 mm and 82.87%), respectively. Among systemic fungicides, complete inhibition of growth was noticed in all the tested concentration of propiconazole and carbendazim + mancozeb at 1500 ppm. In case of bioagents, highest inhibition of growth and width of zone of inhibition were observed in B. subtilis (83.88% and 3.0 mm) and T. asperellium (82.11% and 3.0 mm)

Keywords

Alternaria alternata, Chrysanthemum, Fungicides, Mancozeb, B. subtilis, per cent inhibition

Conclusion

Alternaria alternata causing Alternaria blight on chrysanthemum is common and destructive disease causing 80% yield loss. The pathogen was isolated in PDA media and proved its pathogenicity. Later, the pathogen was identified based on cultural, morphological and molecular characteristics. Testing of different fungicides and bioagents was done in vitro to test their efficacy to inhibit growth of pathogen. In this experiment, mancozeb at 2000, 2500 and 3000 ppm, was equally effective to propineb at 2500 and 3000 ppm and copper oxychloride and chlorothalonil at 3000 ppm, all the tested concentration of propiconazole and carbendazim+ mancozeb at 1500 ppm are found to be effective in maximum inhibition of growth of the pathogen

References

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How to cite this article

Sowmya M., S. Narasimha Rao, A. Snehalatha Rani and T. Suseela (2024). Isolation, Identification of Alternaria alternata causing Leaf Blight in Chrysanthemum and its Management. Biological Forum – An International Journal, 16(10): 12-18